Using time-resolved infrared–vacuum-ultraviolet double-resonance spectroscopy, experimental room-temperature measurements of state-to-state rate coefficients for rotational energy transfer within the $X{}^1{\mathrm{\Sigma }}^{+}(v=2)$ vibrational state of CO due to ${\mathrm{H}}_2$ collisions have been compared to accurate four-dimensional close-coupling quantum calculations. Theoretically predicted quantum interferences in the ${\text{CO-H}}_2$ collisional system are experimentally observed at room temperature, and excellent agreement between theory and experiment is observed. These results provide a valuable benchmark for validating the anisotropic part of the potential energy surface, thereby supporting the theoretical modeling of CO emission in warm astrophysical environments such as photodissociation regions.

Close

PrevNext

View figure in article

• Atomic & molecular collisions
• Electronic structure of atoms & molecules
• Interatomic & molecular potentials
• Long-range interactions
• Molecular spectra
• Potential energy surfaces
• Rotational states
• van der Waals interaction